1. Field of the Invention
The present invention pertains to a double clutch assembly, comprising a first clutch area for the optional production of a first torque-transmitting connection between a drive element and a first driven element, and a second clutch area for the optional production of a second torque-transmitting connection between the drive element and a second driven element.
2. Description of the Related Art
Double clutch assemblies of this type are used, for example, in conjunction with variable gear transmissions which have two transmission input shafts. Different gear stages can be engaged, depending on which of the transmission input shafts is in the torque-transmitting path after actuation of the associated clutch area. To implement the engagements and disengagements of the clutch, it is known in double clutch assemblies of this type that each clutch area can have its own, separate engaging/disengaging mechanism, so that, depending on the actuation or activation of one of the engaging/disengaging mechanisms, one of the clutch areas can be disengaged while the other is or becomes engaged. This leads to a relatively complicated design, however, because the two engaging/disengaging mechanisms, such as engaging/disengaging piston-cylinder assemblies, must be installed in a small space and thus staggered radially with respect to each other.
The object of the present invention is to improve the double clutch assembly of the general type in question so that, with a simpler design for executing engagements and disengagements, the various clutch areas can be activated in a simplified manner.
This object is accomplished according to the invention by a double clutch assembly, comprising a first clutch area for the optional production of a torque-transmitting connection between a drive element and a first driven element and a second clutch area for the optional production of a torque-transmitting connection between the drive element and a second driven element. The first and second driven elements may be embodied as coaxially positioned transmission input shafts.
The double clutch assembly according to the invention has a common engaging/disengaging mechanism, by means of which the first and the second clutch area can be actuated to produce or to nullify the torque-transmitting condition.
According to the invention, therefore, the principle of providing a separate engaging/disengaging mechanism for each clutch area, these separate mechanisms then also being actuated separately, is abandoned. Instead, a single mechanism of this type is provided, which, depending on how it is actuated, can have the effect either of engaging one of the clutch areas while disengaging the other or of keeping both clutch areas in a state of partial torque transmission. This considerably simplifies both the design of a clutch assembly of this type and the measures required to actuate the clutch.
In accordance with the invention, it is then also provided preferably that, when one of the clutch areas has been actuated by the engaging/disengaging mechanism to produce the torque-transmitting condition, the other clutch area is actuated to nullify the torque-transmitting condition.
The double clutch assembly according to the invention can have, for example:
a first pressure plate for the first clutch area, this plate being provided with a first friction surface, which can be brought to rest against a first clutch disk assembly;
a second pressure plate for the second clutch area, this plate being provided with a first friction surface, which can be brought to rest against a second clutch disk assembly; and
an essentially stationary intermediate disk assembly, which has, on one side, a second friction surface for the first clutch area and, on the other side, a second friction surface for the second clutch area, where, to create the torque-transmitting condition for the first clutch area, the first pressure plate can be moved toward the intermediate disk assembly and, to create the torque-transmitting condition of the second clutch area, the second pressure plate can be moved toward the intermediate disk assembly.
To minimize the actuation effort required to actuate the clutch assembly and to shift from one of the clutch areas to the other, the double clutch assembly according to the invention is provided with a force storage unit, by means of which one of the clutch areas is kept pretensioned in its torque-transmitting state.
A design which is very simple to build can be obtained in this case by providing the force storage unit with a first force storage element, which is or can be supported on one side against the pressure plate of the one clutch area and on the other side against a component which transmits the engaging force. By means of this engaging force-transmitting component, an engaging force can be transmitted from a force-generating mechanism to the pressure plate of the other clutch area.
So that both clutch areas can take equal advantage of the movements of the engaging force-transmission component when these two clutch areas are being engaged and disengaged, the part of the engaging force-transmission component which cooperates with the first force storage element can be moved away from the pressure plate of the one clutch area when an engaging force is transmitted to the pressure plate of the other clutch area.
The effort required to construct the clutch assembly and to actuate it to execute the various engagements and disengagements can be further simplified by providing the engaging force-transmission component with a second force storage element, which has an area which cooperates with the first force storage element, this area of the second component being pretensioned in the direction toward the pressure plate of one of the clutch areas. By keeping one of the clutch areas pretensioned in its torque-transmitting state, the only measure which must be taken to switch from the one clutch area to the other is to generate an actuating force in a single direction, whereas shifting back in the other direction can be accomplished simply by ceasing to generate this force.
To simplify the design even further, the first force storage element is permanently connected to the second force storage element, the two preferably being designed as a single unit. This can be realized, for example, by designing the first force storage element with a plurality of force storage sections projecting from the second force storage element toward the pressure plate of one of the clutch areas.
To ensure, in a double clutch assembly according to the invention, that the actuating characteristic and the clutch characteristic do not change over the service life of the system, that is, even after wear has occurred, the first force storage element cooperates with the pressure plate of one of the clutch areas and/or the engaging force-transmission component cooperate with the pressure plate of the other clutch area by way of wear compensation assemblies.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.